1. Field of the invention
This invention relates to automatic fabrication of electrical wiring harnesses and, more particularly, to connectorized harness fabrication for twisted pairs.
2. Description of the Prior Art
The typical prior art method for fabricating wiring harnesses utilizes a peg board upon which individual wires are strung using the pegs for routing. When all the wires of the harness are arranged in a proper physical layout, lashing twine is used to secure the wire bundles in the various branches in order to maintain the physical configuration. Each wire end is separately stripped and each wire is color coded or marked to identify the proper termination point. The harness can then be taken off of the harness fabrication board and installed in the piece of electrical equipment for which it is intended. Finally, a craftsperson must attach each individual wire end to the proper terminal in the electrical appartus.
This technique for wiring electrical apparatus using prefabricated harnesses is slow, expensive, tedious, and usually results in a substantial number of wiring errors. Since the entire operation is manual, wire ends and individual wires must be indentified by a craftsperson during both fabrication and installation of the harness.
Flat cable harnesses in which the wires of the harness are fabricated in a continuous web together in a preselected orientation by insulation bridges between the various wires reduces some of these problems. An operator is still required, however, to identify and handle each of the wires in order to install the harness.
It is sometimes desirable in such prior art harness-making systems to attach connector blocks of some sort to the ends of the wires in order to simplify the installation procedure. Although such connector blocks reduce the labor involved in installing the harness, the same labor is merely transferred to the harness-making station since the individual ends of the wires must be indentified in order to attach them to the connector block. One such system is shown in P. W. Mercer U.S. Pat. No. 3,842,496, granted Oct. 22, 1974. A similar technique, using a flat cable harness, is shown in L. H. Hilderbrandt U.S. Pat. No. 3,836,415, granted Sept. 17, 1974. Yet other connectorized harness fabrication systems are shown in E. E. Folkenroth U.S. Pat. No. 3,859,724, granted Jan. 14, 1975, and R. A. Long et al U.S. Pat. No. 3,885,287, granted May 27, 1975.
Each of these prior art harness-making systems involve considerable manual manipulation of the harness parts and connector blocks and none is suitable for twisted pairs of telephone wires.